function s1_goto_dir(){
  cd "$1"
}

function s2_touch_empty_file_with_given_name(){
  touch "$1"
}

function s3_make_directories(){
  mkdir -p projects/{git,backup}
}

function s4_create_6_files(){
  touch projects/linux{1,2}_{centos,redhat,c_programming}
}

function s5_make_directories_in_git(){
  mkdir -p projects/git/{linux1,linux2}
}

function s6_move_files_to_dir_1_or_2(){
  mv projects/linux1_* projects/git/linux1&&mv projects/linux2_* projects/git/linux2
}

function s7_create_package_and_compress(){
  tar -czvf projects/backup/git.tar.gz projects/git
}

function s8_delete_dir_git(){
  rm -rf projects/git
}

function s9_recover_from_git_tar_gz_backup(){
  tar -zxvf projects/backup/git.tar.gz -C ./
}

function s10_create_package_and_compress(){
  tar -jcvf projects/backup/git.tar.bz2 projects/git
}

function s11_find_and_sort_alphabetically_all_created_files_and_dirs(){
  find ./projects |sort
}

function s12_get_next_15_minutes_boundary(){
  date +'%Y-%m-%d_%H:%M:%S' -d @$(($(date+%s)/900*900+900))
}


